final RegExp firstNameRegex = RegExp(r'^[A-Za-z]+$'); // Only letters
final RegExp lastNameRegex = RegExp(r'^[A-Za-z]+$'); // Only letters
final RegExp emailRegex = RegExp(
    r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'); // Standard email format
final RegExp bankAccountNumberRegex =
    RegExp(r'^\d{10,20}$'); // A number with 10 to 20 digits
